Calipering device



F. P. CLARK CALIPERING DEVICE March 23, 1943.

Filed Jan. 5, 1942 2 Sheets-Sheet 1 FRANK P. CLARK- Patented Mar. 23,1943 UNITED STATES PATENT OFFICE 2,314,480 CALIPERING DEVICE Frank P.Clark, St. Paul, Minn. Application January 5, 1942, Serial No. 425,650

Claims.

, were pre-machined, the machinist was still confronted with a difiiculttask in machining or filing the key blank in order that an accurate fitwas obtained so that the key would lock the gear rotatable with theshaft without play. With my method the process of fitting a key into akeyway is not only accurate, but may be accomplished with much lesslabor and thus a shorter period of time is required to make and fit thekeys for any key-way.

By my method I have accomplished a means of eliminating the work offiling and fitting the key blank for a shaft key. To carry out my methodI have provided a key-way caliper which may be readily inserted into akey-way to take accurate dimensions and thereby simplify the process ofmaking a shaft key. My key-way caliper is constructed to correctlymeasure the height, taper and width of a key-way.

In carrying out my method my caliper may be adjusted by means of aseries of various sized blocks which may be securely attached to theunder side of my key-way caliper and which will enable the key-waycaliper to measure different size key-ways. By providing a series ofdifferent size blocks I have accomplished a means wherein a single keygauge may be used to dimension numerous sizes of key-ways. Without suchan additional feature it would be necessary to provide more than onekey-way caliper to do the work which one key-way caliper can accomplish.

It is also an object of the present invention to provide a key-waycaliper having means which are adapted to lock the caliper with anaccurate dimension of the key-way slot. The locking knobs of the calipermay be provided with a series of apertures therein which provide meansofinserting a rod into the knobs to help tighten the same. i

It is a further feature of my invention to provide a means whereby thekey-way caliper may be adjusted longitudinally. By providing such ameans the key-way caliper may be used to take measurements for differentsize keys for various key-ways.

It is a further feature of the present invention to provide a key-waycaliper which is adapted to measure a key-way which has been cut in fromthe ends of a shaft. While it has been common practice heretofore toprovide pre-machined 'key blanks which had to be filed by the machinistin order that they could be fitted tightly into a'key-way, in fittingthe key into a key-way which is cut in from the ends of a shaft, it israther difiicult to accurately fit the key. By my method and with mycaliper, all that is necessary is to insert the caliper into the keyway,set the caliper, lock the same by tightening the turn knobs, and thenremove the caliper from the key-way, giving the machinist an accuratedimension of the key-way.

In carrying out my method I employ a jig which I have designed, tosupport a floating table which receives the caliper. My stationary jigis provided with means for attaching the same to a milling machine, ashaper, or to numerous other types of standard machinery now in use inmachine shops. The floating table of my jig is constructed so as to beadjustable with regard to the frame of the jig and is also provided withmeans whereby it can be securely locked in place with regard to theframe. The floating table is also provided with a pair of locking leverswhich provide a means of clamping the key blank securely in place.

It is a further object of the present invention to provide a pair ofadjustable jacks removably secured to the frame of the jig and which areadapted to aid in holding the floating table against chattering whilethe key blank is being cut. The jacks are each provided with a roundbearing head and a large adjusting nut and are further provided with aprojecting lug at the base end thereof which is adapted to fit into anaperture in the base of the frame of the jig to hold the jack in place.i

It is also a feature of the" present invention to provide a pair ofcoiled springs which are adapted to resiliently support the floatingtable while it is being adjusted and locked to the frame of the jig.After a dimension for a key-way has been taken by means of the caliper,the caliper is then used to adjustthe floating table in regard to theframe of the jig. The caliper is then used to set the floating table inthe proper position on the frame of the jig.

In carrying out my method, the jig is attached floating table of the jigis adjusted into proper position, using the key caliper to set thefloating table in working position, and when so set a key blank may becut in accordance with the respective dimension taken by the key-waycaliper. Thus my method enables a machinist to first use the key-waycaliper to get the accurate dimensions for the key, and then to set thejig for holding the key blanks in proper working position, whereupon theblank may be machined to the exact dimension so that the key will fitthe key-way, thus overcoming the necessity of the hand fitting of thekey and the pre-machining of the same. In this manner my methodsaveslabor and time in fitting a key into a key-way.

For the purpose of describing my method I have illustrated certainapparatus in thedrawings:

Figure 1 illustrates a side view of my key-way caliper and a shim blockfor increasing the height of the caliper when desired.

Figure 2 is a plan view of the caliper.

Figure 3' is a longitudinal section on the line 3'-3'of' Figure 2.

Figure 4 is a section on the line i4' of Figure 3.

Figure 5 is a section on the line 5-5 of Figure 3.

Figure 6 is a section on the line 66 of Figure 3.

Figure '7 is a section through a shaft and a member such as a gear orother member desired to be locked to the shaft, and showing my caliperin position to measure the height of the key-way.

Figure 8 is a section on the line 8-8 of Figure 2.

Figure 9 is a perspective of an alternative form of my key-way caliperadapted to take two-Way dimensions simultaneously in a key-way oropening.

Figure 10 is a section through a shaft and member thereon, showing akey-way and my key-way caliper measuring the width of the key-way.

Figure 11 illustrates an end view of the jig used in my method whichholds my caliper and also the key blank in position to be measured.

Figure 12 is a section on the line I2--I2 of Figure 11.

Figure 13 is a plan view of my jig shown in Figure 11.

Figure 14 is a side view on the line I4I4 of Figure 11.

Figure 15 is a sectional detail showing the bed of the floating table ofthe jig shown in Figure 11 cut away to receive a gib key blank in thejig.

Figure 16 is a section of an alternative form of a locking block for thefeeler fingers ofthe caliper.

My caliper-ing device shown in the drawings to assist in carrying out mymethod of making shaft keys and members which are adapted to fit into anopening is illustrated in the device A which is provided with the bodyportion having a fiat baselike channel member III. The member ID haslongitudinal side flanges II which project up from the base Ii] andbetween which a rear fixed block I2 is secured by the screws IS.

The rear fixed block I2 provides a journal for the rear end of theoperating rod I4 which is adapted to be operated by the knob I5. Theinner end of the rod I4 is threaded at I5 into the end block I"! so thatwhen the knob I5 is rotated in one direction the block II will be drawntoward the feeler finger block I2. The feeler finger block I8 ispositioned between the fixed block I2 and the locking'bl'ockv I! whichis threaded to the end It of the rod I4; The finger block I8 is formedwith an elongated opening I9 through which the rod I4 freely passes andby means of a pair of guide posts 20 which are secured to the base plateIE the block I8 is guided in relation to the base II) so as to moveparallel to the base on the guide pins 25. Coil springs 2I rest on topof the guide pins 29 and extend into the recesses 22 in the block I8 toact to automatically urge the feeler block I8 upward away from the plateI0.

Thus when the knob I5 is turned to release the locking block I? fromengagement with the block I3, the feeler block I 8 will be automaticallyraised by the springs 2I. A shoulder 23 is provided on the rod I4adjacent the journal I2 which provides the shoulder means against theside of the journal I2 so that when the knob I5 is rotated to lock theblock I! against the side of the block I8, the shoulder 23 will bindagainst the side of the journal I2, thus locking the feeler finger blockIS in the desired position between the limits of its movement regulatedby the slot I9.

A front feeler block similar to I8 is provided in the feeler block 25which is urged upwardly by the coil springs 23. The feeler block 25 hasan elongated passageway 21 through the same through which the hollowoperating rod 28 freely passes. The rod 28 is operated by the knob 23 torotate the same and is threaded at its inner end 30 to threadedly engagethe locking block 3I which is similar in action to the block I1. Ajournal block 32 is secured by the screw 33 to the base plate II). Thejournal block 32 may be adjusted along the base plate ID, that is, intodifferent positions by means of the series of holes 34 for the screws33. Thus the forward feeler block 25 with its journal 32 may be set intodifferent positions along the base plate II].

The locking blocks I! or 3| may be formed as illustrated by thealternative form of locking block 35, as shown in Figure 16. In thisconstruction of the locking block 36, a brake liner 3? is supported onthe face of the block which is adapted to bind against either of thefeeler fingers It or 25. This braking or friction forming material 37may be of any suitable nature and is adapted to bear against the side ofthe feeler block when the knobs I5 or 29 are operated to draw thelocking block 36 tightly against the surface of the feeler block topositively lock the same. The liner 31 may be of a rubber composition, asoft metal, or like brake lining material, and in fact, may be of anysuitable material to act to increase the locking grip by the block 36 tohold the feeler fingers positively in place once they are set. Thisconstruction prevents the feeler fingers I8 or 25 from moving after oncethey have calipered a key-way so long as the knobs I5 and 29 areoperated into locking position.

The knobs I5 and 29 are provided with key receiving recesses 38 and 39,respectively, to permit the knobs to be operated by a key inserted intothese recesses when it is desired, either to increase the force inlooking the knobs or to operate the knobs when they are in closequarters by means of a key which slips into the recesses 38 and 39.

In carrying out my method it is desirable to use a caliper A in akey-way 40 in a shaft such as II, shown in Figure 7. The wheel or gearhub 42 in which a complemental key-way 43 is provided is in position onthe shaft and the callper A is inserted in the key-ways. When thecaliper A is inserted in the key-Ways 40 and 43 the feeler blocks I8 and25 are released by the knobs I5 and 29, whereupon the springs 2| and 26for the respective feeler blocks I8 and 25 will automatically cause theupper sharp edges of the. feeler blocks to ride up to the surface in thekey-way 3 so as to accurately caliper the incline of the key-way. Thebase Ill of the caliper A rests on the bottom of the key-way 40 in theshaft. When the caliper has been set in the proper position in thekey-ways, either the knob l or the knob 29 may be operated to lock theblocks I1 and 3| against the respective feeler blocks 18 and 25', thuslocking these blocks in the position to accurately caliper thedimensions in the key-ways. By the independent operation of the knobs l5and 29, each of the caliper feeler blocks [8 and 25 may be locked whenin the desired position to caliper the opening.

It is also apparent that as many feeler blocks as may be desired may besupplied in the caliper A and a series of knobs such as 15 and 29 may beprovided for locking the feeler blocks selectively. It is also apparentthat the feeler blocks 18 and 25 may be locked in downward positionbefore the caliper A is inserted in the key-Way openings to becalipered. Then after the caliper is in position, the knobs l5 and 29can be released, thus releasing the feeler blOCkS l8 and and the springsback of the same, causing them to automatically move into position tocaliper the openings by the caliper A. After the caliper has been lockedit is withdrawn from the key-ways and 43 and is ready to be used as agauge for making a key by my method.

My caliper may be set as illustrated in Figure 10, to take thedimensions of the width of a keyway 44 in a shaft 45 which is fitted tothe member 46. Thus the caliper A may caliper the height of the key aswell as the width.

In using my caliper A it may be desirable to build up the base H] of thesame by shim blocks If! such as I have shown in Figure 1. These shimblocks may be of any thickness desired and are adapted to be attached bythe screws 41 which are shown in Figure 1 in position ready to beinserted into the holes 48 shown in Figure 2..

In this manner my caliper A may be used in larger or deeper openings.

Further, my caliper may be made in the form B illustrated in Figure 9,which provides a twoway dimension caliper device with an angle iron baseportion 49 which supports the feeler blocks, their journal blocks, andthe locking blocks, respectively, which are virtually identical to thosedescribed as the bearing blocks l2 and 32. In the form B of my caliper,I provide a pair of feeler blocks I8, one operating from one side of thecaliper and the other operating from the side directly at right anglesto the other. The front pair of feeler blocks 25 operate in the samemanner, and by means of the knobs l5 and 29, the respective pairs offeeler blocks I 8 and 25 may be locked in a set position when they havecalipered the desired opening. With the form of caliper B, the height ofthe key-way and the width of the same may be taken at one time.

A caliper of this character is desirable as it saves time and is adaptedto take the two-way dimensions of a recess in which a member is to befitted and which member must accurately fit the opening calipered, suchas keys and other members being fitted into an opening.

In carrying out my method after the caliper A or B has been locked withthe desired dimensions for a key, it is placed in the machining jig Cillustrated in Figures 11, 12 and 13. The jig C is formed with afloating table 50 which is supported on the vertical wall 5| of theframe of the jig. The jig C is formed with a base portion 52 which maybe clamped by the bolts 53 or any other suitable means, to a shaper,milling machine, or other desirable machine where the key blanks may beaccurately machined.

The floating table 50 is urged upwardly by the c'oil'springs 54 and iskept in close contact under spring tension of the spring 55 to the wall5| so that no dirt or dust may enter between the inner surface of thefloating table 50 and the wall 5|. Thus the floating table is free to bemoved into the desired position. After the table is in the positiondesired, it is locked in place by the locking bolts 56. The frame of thejig C is formed with a horizontal extending flange 51, and it will beapparent that all of the sides of the frame of the jig C, as well as thefloating table 50, are machined accurately so as to be of accuratedimensions and the surfaces are smoothly polished to permit the parts tobe positioned as accurately as possible in place in the J g.

In carrying out my method the caliper A is placed under the flange 5!and the floating table 50 is brought up into contact with the base It]of the caliper A, as illustrated in Figure 11, and then the table 50 islocked in place by the bolts 56, setting the floating table rigidly inplace. When the table 50 is set in this manner, it may be furtherreinforced from the bottom by the adjustable standards 58 which bearagainst the bottom of the table 50 and are locked in place by the nuts59. When the jig C is set up in this manner it is ready to receive a keyblank D which is adapted to be locked in place by the clamp E with thekey blank D resting on the table 50 as illustrated in Figure 11.

In Figure 15 I have illustrated a sectional detail showing a gib keyblank in position on the table 50 and showing the table 50 cut out toreceive the head 60 of the'g'ib key.

; It will be apparent from Figure 12 that the table 59 may be adjustedto the dimensions of the caliper A so that when the table 50 of the jigis in the desired position and the key blank D is clamped in place, thekey blank may be machined to the dimensions of the caliper so that whenthe key blank is fully machined it may be placed in the key-ways andwill fit accurate in place if it has been made in accordance with thedimensions of the setting of the caliper A.

Figure 14 illustrates a side view with the key blank D in place readyfor machining and the clamps E fixed to the table 55. Figure 13illustrates a plan view of the jig C and shows the key blank D inposition to be machined. An adjustable end shoulder 6! is provided atone end of the table 5!! which has an adjusting screw 62 to adjust thelongitudinal position of the key blank D and to act as a shoulder at theend of the key blank to assist in holding the key longitudinally as itis machined in a direction toward the shoulder Bl. Thus the key blank isheld firmly in place.

It is therefore apparent that my method of making keys by a completemachining job of the key blank is quite simple when it is carried out bymeans of my caliper A or B. First, the dimension of the key-way is takenby the caliper, the caliper is locked with these dimensions so that inhandling the caliper the dimensions will not be changed, then thecaliper is placed in the jig C and locked in position under thelongitudinal flange or shoulder 51, setting the floating table of thejig in proper position, whereupon a key blank is locked in properposition on the table 50 and the whole jig is positioned in a shaper,milling machine or other similar machine adapted-to operate to machinethe key blank D accurately. In this manner, keys may be made for shaftsor a member may be accurately made to fit a certain size opening withoutrequiring filing and fitting as has usually been the case in formermethods. If the key blanks are'properly machined to the dimensions ofthe caliper A, they will fit the key-way without further machining orfinishing. I have found that this method is very desirable as it is moreeconomical, more accurate, and much faster than the old method.

The caliper B when used to take two dimensions of an opening can befirst clamped in the jig C in position to permit the machining of thekey or member in one direction, and then after the blank is machined tothe first dimension the caliper B can be clamped in the jig for theother dimension. and then the blank can be machined to this lastdimension. Thus two dimensions of a key-way or other opening may betaken at one time by the alternative form of caliper B and the member orkey blank can be finished while clamped in the jig C with thesedimensions. Then, when the blank is in finished form it is ready to fitthe opening for which it is intended without further machining, filingor fitting.

In accordance with the patent statutes, I have described the principlesof operation of my calipering device and the method of making shaftkeys, and while I have endeavored to set forth the best embodimentthereof, I desire to have it understood that this is only illustrativeof a means of carrying out my invention and that obvious changes may bemade within the scope of the following claims without departing from thespirit of my invention.

I claim 1. A caliper for shaft key-ways comprising an elongated basemember, pairs of blocks mounted at spaced positions on said base member,feelers floatingly held between the blocks of each pair andspring-pressed to an outward position, whereby the caliper may beinserted in a keyway closed at one end and the feelers willautomatically position themselves to contact a wall of said key-way, andmeans for locking said feelers in their automatically adjusted position.

2. A caliper for shaft key-Ways comprising an elongated base member,pairs of blocks mounted at spaced positions on said base member, feelersfloatingly held between the blocks of each pair and spring-pressed to anoutward position,

whereby the caliper may be inserted in a key way closed at one end andthe feelers will automatically position themselves to contact a wall ofsaid key-way, and means for. locking. said feelers in theirautomatically adjusted position, said means including an operatingmember for each pair of blocks extending beyond said base member at theend of the caliper opposite that end which is inserted in the key-way.

3. A caliper for shaft key-ways comprising an elongated base member,pairs of blocks mounted at spacedpositions on said base member, one ofeach pair being fixed thereto and the other being slidable thereon,feelers fioatingly held between the blocks of each pair andspring-pressed to an outward position, whereby the caliper may beinserted in a key-way closed at one end and the feelers willautomatically position themselves to contact a Wall of said key-way, andmeans extending beyond one end of the basemember for sliding theslidable block of each pair to lock the feelers in their automaticallyadjusted position.

4. A caliper for shaft key-ways comprising an elongated base member,pairs of blocks mounted at spaced positions on said base member, one ofeachpair being fixed thereto and the other being slidable thereon,feelers fioatingly held between the blocks of each pair andspring-pressed to an outward position, whereby the caliper may beinserted in a key-way closed at one end and 'the feelers willautomatically position themshaft and the second of said fixed blocks andthreaded into the second slidable block whereby the feelers may beclamped between the blocks of each pair in their automatically adjustedposition.

5. A caliper for shaft key-ways comprising an elongated base member,pairs of blocks mounted at spaced positions on said base member, feelersfloatingly held between the blocks of each pair and spring-pressed to anoutward position whereby the caliper may be inserted in a key-way closedat one end and the feelers will automatically position themselves tocontact a wall of said key-way, means-holding the blocks on the basemember so that said blocks may be adjusted longitudinally of the basemember, and means for locking said feelers in their automaticallyadjusted position.

FRANK P. CLARK.

